Epoxide hydrolases (EHs) catalyze the hydrolysis of aliphatic epoxides or arene oxides to their corresponding diols by the addition of water (see, Oesch, F., et al., Xenobiotica 1973, 3, 305-340). Some EHs play an important role in the metabolism of a variety of compounds including hormones, chemotherapeutic drugs, carcinogens, environmental pollutants, mycotoxins, and other harmful foreign compounds.
There are two well-studied EHs, microsomal epoxide hydrolase (mEH, EC 3.3.2.9) and soluble epoxide hydrolase (sEH, EC3.3.2.10). These enzymes are very distantly related, have different subcellular localization, and have different but partially overlapping substrate selectivities. The soluble and microsomal EH forms are known to complement each other in degrading some plant natural products (see, Hammock, B. D., et al., COMPREHENSIVE TOXICOLOGY. Oxford: Pergamon Press 1997, 283-305 and Fretland, A. J., et al., Chem. Biol. Intereract 2000, 129, 41-59).
The major role of the sEH is in the metabolism of lipid epoxides including the metabolism of arachidonic acid (see, Zeldin, D. C., et al., J. Biol. Chem. 1993, 268, 6402-6407), linoleic acid (see, Moghaddam, M. F., et al., Nat. Med. 1997, 3, 562-567), and from other fatty acids some of which are endogenous chemical mediators (see, Carroll, M. A., et al., Thorax 2000, 55, S13-16). Epoxides of arachidonic acid (cis-epoxyeicosatrienoic acids or EETs) and other lipid epoxides are known effectors of blood pressure (see, Capdevila, J. H., et al., J. Lipid. Res. 2000, 41, 163-181), and modulators of vascular permeability (see, Oltman, C. L., et al., Circ Res. 1998, 83, 932-939). The vasodilatory properties of EETs are associated with an increased open-state probability of calcium-activated potassium channels leading to hyperpolarization of the vascular smooth muscle (see Fisslthaler, B., et al., Nature 1999, 401, 493-497). Hydrolysis of the EETs by sEH diminishes this activity (see, Capdevila, J. H., et al., J. Lipid. Res. 2000, 41, 163-181). Hydrolysis of EETs by sEH also regulates their incorporation into coronary endothelial phospholipids, suggesting a regulation of endothelial function by sEH (see, Weintraub, N. L., et al., Am. J. Physiol. 1992, 277, H2098-2108). It has been shown that treatment of spontaneous hypertensive rats (SHRs) with selective sEH inhibitors significantly reduces their blood pressure (see, Yu, Z., et al., Circ. Res. 2000 87, 992-998). In addition, it was claimed that male knockout sEH mice have significantly lower blood pressure than wild-type mice (see Sinal, C. J., et al., J. Biol. Chem. 2000, 275, 40504-405010), however subsequent studies with back breeding into C57b mice demonstrated that 20-HETE levels increased compensating for the increase in plasma EETs (see, Luria, A. et al., J. Biol. Chem. 2007, 282:2891-2898.
The EETs have also demonstrated anti-inflammatory properties in endothelial cells (see, Node, K., et al., Science 1999, 285, 1276-1279 and Campbell, W. B. Trends Pharmacol. Sci. 2000, 21, 125-127). In contrast, diols derived from epoxy-linoleate (leukotoxin) perturb membrane permeability and calcium homeostasis (see, Moghaddam, M. F., et al., Nat. Med. 1997, 3, 562-567), which results in inflammation that is modulated by nitric oxide synthase and endothelin-1 (see, Ishizaki, T., et al., Am. J. Physiol. 1995, 269, L65-70 and Ishizaki, T., et al., J. Appl. Physiol. 1995, 79, 1106-1611). Micromolar concentrations of leukotoxin reported in association with inflammation and hypoxia (see, Dudda, A., et al., Chem. Phys. Lipids 1996, 82, 39-51), depress mitochondrial respiration in vitro (see, Sakai, T., et al., Am. J. Physiol. 1995, 269, L326-331), and cause mammalian cardiopulmonary toxicity in vivo (see, Ishizaki, T., et al., Am. J. Physiol. 1995, 269, L65-70; Fukushima, A., et al., Cardiovasc. Res. 1988, 22, 213-218; and Ishizaki, T., et al., Am. J. Physiol. 1995, 268, L123-128). Leukotoxin toxicity presents symptoms suggestive of multiple organ failure and acute respiratory distress syndrome (ARDS) (see, Ozawa, T. et al., Am. Rev. Respir. Dis. 1988, 137, 535-540). In both cellular and organismal models, leukotoxin-mediated toxicity is dependent upon epoxide hydrolysis (see, Moghaddam, M. F., et al., Nat. Med. 1997, 3, 562-567; Morisseau, C., et al., Proc. Natl. Acad. Sci. USA 1999, 96, 8849-8854; and Zheng, J., et al., Am. J. Respir. Cell Mol. Biol. 2001, 25, 434-438), suggesting roles for sEH in the regulation of inflammation and vascular permeability. The bioactivity of these epoxy-fatty acids suggests that inhibition of vicinal-dihydroxy-lipid biosynthesis may have therapeutic value, making sEH a promising pharmacological target.
1,3-disubstituted ureas, carbamates, and amides have been reported as new potent and stable inhibitors of sEH (See, U.S. Pat. No. 6,150,415). These compounds are competitive tight-binding inhibitors with nanomolar KI values that interact stoichiometrically with purified human recombinant sEH (see, Morisseau, C., et al., Proc. Natl. Acad. Sci. USA 1999, 96, 8849-8854). Based on the X-ray crystal structure, the urea inhibitors were shown to establish strong hydrogen bonds between the urea group of the inhibitor and residues of the sEH active site, mimicking features encountered in the reaction coordinate of epoxide ring opening by this enzyme (see, Argiriadi, M. A., et al., Proc. Natl. Acad. Sci. USA 1999, 96, 10637-10642 and Argiriadi, M. A., et al., J. Biol. Chem. 2000, 275, 15265-15270). These inhibitors efficiently reduced epoxide hydrolysis in several in vitro and in vivo models (see Yu, Z., et al., Circ. Res. 2000, 87, 992-998; Morisseau, C., et al., Proc. Natl. Acad. Sci. USA 1999, 96, 8849-8854; and Newman, J. W., et al., Environ. Health Perspect. 2001, 109, 61-66). Despite the high activity associated with these inhibitors, there exists a need for compounds possessing similar or increased activities, preferably with improved water solubility and/or pharmacokinetic properties to facilitate formulation and delivery.
The present invention provides such compounds along with methods for their use and compositions that contain them.